On the Central Position of "The Negation of Negation" in the Whole Process of Development of A Thing

While Lenin claims that law of unity of opposites is essence and core of dialectics,Engels thinks that The of Negation is core of whole process of development of a thing.The former refers to position of law of unity of opposites in dialectic theoretical system,and latter is for position of second negation,the third phase(The of Negation) in whole process of development of a thing.Lenin and Engels make judgment on position and function of different components in dialectic theoretical system from different perspectives and levels,which supplemented with each other.We cannot apply affirmation and negation to take place of negation of negation because it fails to describe process of a thing's self-development and self-improvement.The law of unity of opposites and quality contingent negative variation rule can neither describe circulation and whole process,nor states that development is the repetition of some characteristics in lower level happens in higher level. However,only The of Negation can illustrate such a characteristic.Therefore,we should adhere to unity of commonality and specialty of The of Negation so as to master circulation of whole process of development of a thing.